Causes and Clinical Context of Myelopathy

Primary Etiologic Categories

• Degenerative cervical spine disease is the most common cause of myelopathy, particularly in the context of progressive hand weakness and numbness, with disc herniations, osteophyte formation, and spinal canal narrowing being the primary contributing factors, according to the American College of Radiology 1, 2
• Cervical spondylotic myelopathy represents the most frequent cause of spinal cord dysfunction in adults, accounting for the majority of chronic myelopathy cases, as stated by the American College of Radiology 1, 2
• Disc herniations compressing the spinal cord anteriorly is a contributing mechanism, as reported by the Journal of the American College of Radiology 3, 1
• Osteophyte formation from posterior vertebral body edges is another contributing factor, according to the American College of Radiology 2, 1
• Congenitally short pedicles that accentuate compression is also a contributing factor, as stated by the Journal of the American College of Radiology 3
• The cervical spine is predominantly affected due to its mobility and degenerative susceptibility, as reported by the American College of Radiology 1, 2

Compressive Causes

• Epidural abscess causes acute compression with severe back pain, fever, and rapidly progressive deficits, according to the Journal of the American College of Radiology 3, 2
• Epidural hematoma can develop spontaneously or post-traumatically, as reported by the Journal of the American College of Radiology 3
• Epidural lipomatosis represents a rarer compressive cause, according to the American College of Radiology 1
• Metastatic epidural spinal cord compression affects 2.5-5% of cancer patients, with back pain occurring in 88-90%, as stated by the American College of Radiology 2
• Primary or metastatic tumors in extradural and intradural extramedullary spaces cause progressive compression, according to the Journal of the American College of Radiology and the American College of Radiology 3, 2

Vascular Causes

• Ischemic myelopathy most commonly results from atheromatous disease or complications of aortic surgery in adults, as reported by the Journal of the American College of Radiology and the American College of Radiology 3, 2
• Systemic hypotension, thoracoabdominal aneurysms or dissection, sickle cell disease, and fibrocartilaginous embolic disease are additional predisposing factors, according to the Journal of the American College of Radiology 3
• Spinal arteriovenous malformations can cause progressive myelopathy through venous hypertension, as stated by the Journal of the American College of Radiology and the American College of Radiology 3, 2

Inflammatory and Demyelinating Causes

• Multiple sclerosis involves the spinal cord in 80-90% of patients, most commonly affecting the cervical cord, according to the American College of Radiology 2
• Multiple sclerosis presents with incomplete transverse myelitis, Lhermitte's sign, and asymmetric deficits, as reported by the American College of Radiology 2
• Neuromyelitis optica is characterized by longitudinally extensive transverse myelitis with severe bilateral motor weakness, according to the American College of Radiology 2

Infectious Causes

• Human T-cell lymphotropic virus myelitis, tuberculosis, schistosomiasis, and HIV vacuolar myelopathy are infectious causes of myelopathy, as stated by the American College of Radiology 1, 2

Metabolic Causes

• Vitamin B12 deficiency leading to subacute combined degeneration and copper deficiency myelopathy are metabolic causes of myelopathy, according to the American College of Radiology 1

Diagnostic Considerations

• The degree of radiographic abnormality may not correlate with symptom severity, as reported by the American College of Radiology 1
• MRI with and without contrast is essential to distinguish compressive from non-compressive etiologies and to evaluate for inflammatory, infectious, or neoplastic causes, according to the American College of Radiology 1, 2

Band‑Like Sensation in Non‑Compressive Thoracic Myelopathy

Clinical Significance

• A circumferential “band‑like” sensory disturbance around the trunk is a hallmark of thoracic myelopathy; when the lesion is non‑compressive, the most frequent etiologies are demyelinating diseases (especially multiple sclerosis), spinal cord ischemia, and metabolic myelopathies such as vitamin B12 deficiency. [4][5]

Common Non‑Compressive Etiologies

Demyelinating Disorders

• Multiple sclerosis involves the spinal cord in 80–90 % of patients, usually the cervical cord, but thoracic involvement can produce the classic band‑like sensation. 5
• MS spinal cord lesions are typically ≤2 vertebral segments long, located peripherally in the lateral and posterior columns, and appear wedge‑shaped on axial MRI. 6
• Neuromyelitis optica (NMO) causes longitudinally extensive transverse myelitis (≥3 vertebral segments) with a characteristic cloud‑like contrast enhancement that differentiates it from MS. 6

Vascular Disorders

• Spinal arteriovenous malformations generate progressive myelopathy through venous hypertension, showing dorsal cord edema and enlarged perimedullary veins on imaging. 5

Metabolic Disorders

• Vitamin B12 deficiency leads to subacute combined degeneration with T2 hyperintensity of the posterior and lateral columns, without contrast enhancement. 5

Infectious Disorders

• Infections such as human T‑cell lymphotropic virus myelitis, tuberculosis, HIV‑associated vacuolar myelopathy, and schistosomiasis can produce non‑compressive myelopathy with band‑like sensory levels. 5

Diagnostic Imaging Strategy

• MRI of the entire spine with and without intravenous contrast is essential to separate compressive from non‑compressive causes and to assess for inflammatory, infectious, or neoplastic processes. [5][7]
• Diffusion‑weighted imaging (DWI) should be added when spinal cord ischemia is suspected, because DWI detects signal changes earlier than conventional T2‑weighted sequences. 7

Contrast‑Enhancement Patterns (Diagnostic Clues)

These patterns help narrow the differential diagnosis. 6

Imaging Findings by Etiology

• Multiple sclerosis – Small, focal lesions ≤2 segments, peripheral (lateral/posterior) location, wedge‑shaped on axial views. 6
• Neuromyelitis optica – Longitudinally extensive lesions (≥3 segments), central gray‑matter involvement, cloud‑like enhancement. 6
• Metabolic myelopathy (e.g., B12 deficiency) – Posterior and lateral column T2 hyperintensity without post‑contrast enhancement. 5
• Ischemic myelopathy – Central gray‑matter involvement producing the “owl’s eyes” sign on T2, with restricted diffusion on DWI. 7

Guideline Recommendations for Neurosarcoidosis Diagnosis

Etiology Listing in Professional Guidelines

• The American College of Radiology (ACR) guidelines list systemic inflammatory conditions, including sarcoidosis, as recognized causes of inflammatory myelopathy【8, 9】.

Imaging Protocol Recommendations

• The ACR recommends performing a contrast‑enhanced MRI of the entire spine to detect the characteristic enhancement patterns of neurosarcoidosis【8, 9】.